<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      /* .triangle {
        width: 80px;
        height: 100px;
        background-color: skyblue;
        clip-path: polygon(0 0, 0% 100%, 100% 50%);
      } */
      .ab {
        width: 0;
        height: 0;
        border: 100px solid transparent;
        border-left-color: green;
      }
    </style>
  </head>
  <body>
    <!-- <div class="triangle"></div> -->
    <div class="ab"></div>
  </body>
</html>
